[CB-2682] [CB-2683] add prompt dialog to Notification API for WP
add ubuntu platform
1. Added amazon-fireos platform.
2. Change to use amazon-fireos as a platform if user agent string contains 'cordova-amazon-fireos'.
Merge branch 'dev' of github.com:archananaik/cordova-plugin-dialogs into dev
Merge branch 'master' of https://github.com/sgrebnov/cordova-plugin-dialogs
added ubuntu support
[CB-5565] Updated version and RELEASENOTES.md for release 0.2.4
Merge branch 'dev'
[CB-5565] Incremented plugin version on dev branch.
CB-3762 Change prompt default to empty string
move images from css to img
Merge branch 'master' of github.com:zalun/cordova-plugin-dialogs into dev
Merge branch 'dev' of https://git-wip-us.apache.org/repos/asf/cordova-plugin-dialogs into dev
Merge remote-tracking branch 'cordova/dev' into dev